The arylomycin class of natural product, which includes the arylomycin A and B series, was initially discovered by the group of Hans-Peter Frielder, and described in a 2002 publication in the Journal of Antibiotics (J. Schimana, et al., J. Antibiotics (2002), 55(6), 565-570 and 571-577). The arylomycins, as characterized in this publication, comprise a unique structural class of natural product composed of a hexapeptide with a unique biaryl bridge between N-methyl-4-hydroxyphenylglycine−5 (MeHpg5) and tyrosine-7, and N-terminal acyl tails of various lengths. See FIG. 1 showing the structures of natural products of the arylomycin A and B classes as determined by the Frielder group.
The initial report describing the arylomycins provided data describing the antibiotic activity of these compounds again the soil bacteria, Arthrobacter globiformis DSM20124, Arthrobacter oxygans DSM 6612, Arthrobacter pascens DSM 20545, Rhodococcus erythropolis DSM 1069 (currently characterized Rhodococcus opacus), Streptomyces viridochromogenes Tu 57, and Brevibacillus brevis DSM 30, and against the fungus Mucor hiemalis Tu 179/180. The data appear to suggest and the authors conclude that the arylomycins have limited to no activity against the examined bacteria with the exception of Rhodococcus opacus and Brevibacillus brevis. Furthermore while no data is provided, the authors state that no the arylomycin lack activity against the Gram-negative bacteria Escherichia coli K12, Proteus mirabilis ATCC 35501, Pseudomonas fluorescens DSM 50090 and against the eukaryotic organisms Saccharomyces cerevisiae ATCC 9080, Botrytis cinerea Tu 157 and against the green algae Chlorella fusca and against the duckweed Lemna minor. 
In 2004 Kulanthaivel, et al., independently discovered a subclass of the arylomycins, the lipoglycopeptides, which differ from the arylomycin A and B series via glycosylation and aromatic hydroxylation of the hydroxyphenylglycine residue as well as in the length of the N-terminal acyl tail. Kinetic evidence was provided to support the conclusion that the lipoglycopepetides inhibit the essential bacterial enzyme type I signal peptidase in vitro. However, most active members of the lipoglycopeptides displayed only moderate whole cell activity against the human pathogen Streptococcus pnemoniae R6, and extremely little to no activity against the human pathogens Staphylococcus aureus ATCC13709, Haemophilus influenzae ATCC49247, and Escherichia coli K12. Furthermore the intrinsic resistance of E. coli K12 to the lipoglycopeptide subclass of arylomycins was attributed to outer membrane penetrance of drug efflux based on genetic data, suggesting that the arylomycins are not suitable as antimicrobial agents against Gram-negative bacteria. See U.S. Pat. No. 6,951,840, issued Oct. 4, 2005; see also P. Kulanthaivel, et al., J. Biol. Chem. (2004), 279(35), 36250-36258.
The natural products as described by Frielder and Kulanthaivel are as shown in FIG. 1; the compounds termed “arylomycins” by Frielder's group, and the compounds termed “lipoglycopeptides” by the Lilly workers including Kulanthaivel.
A total synthesis of arylomycin A2 has been reported by the inventors herein, see T. Roberts, et al. (2007), J. Am. Chem. Soc. 129, 15830-15838.